Uploaded August 2023 | Updated September 2026, 2 weeks ago
Typically attributed to 6th Century B.C. Greek mathematician and philosopher Pythagoras of Samos, the Pythagorean or "Greedy" Cup works like a normal cup when filled up to an inscribed line, but drains its contents when overfilled - teaching the user a lesson about overindulgence.
The cup works via the principle of the siphon, a channel that allows fluid to be transferred from a higher elevation to a lower one while passing through an even higher point. While siphons have been used for thousands of years, the physics of their operation are more complex and mysterious than they might appear, and have been the subject of much experimentation and scientific debate - even up to the present day.
SOURCES:
ncbi.nlm.nih.gov/pmc/articles/PMC3994459
web.archive.org/web/20130729020731/http://www.mindspring.com/~rwramette/nokes.pdf
https://www.phys.uhh.hawaii.edu/documents/TPT-final.pdf
http://hawaii.edu/news/article.php?aId=4128
commons.wikimedia.org/w/index.php?title=File%3AWould_a_siphon_flow_in_a_vacuum_experimental_answers.pdf&page=1
ncbi.nlm.nih.gov/pmc/articles/PMC4667279
sifouniospottery.com/pythagorean-cups
ancient-origins.net/news-history-archaeology/practical-joke-or-practicing-restraint-drinking-vessel-turned-greedy-guests-021789
https://davidson.weizmann.ac.il/en/online/scienceathome/amazing-self-emptying-cup-pythagoras-cup
romanaqueducts.info/siphons/siphons.htm
https://eprints.qut.edu.au/41923/1/The_secret_siphon_eprints.pdf
iopscience.iop.org/article/10.1088/0031-9120/6/5/005/pdf
Typically attributed to 6th Century B.C. Greek mathematician and philosopher Pythagoras of Samos, the Pythagorean or "Greedy" Cup works like a normal cup when filled up to an inscribed line, but drains its contents when overfilled - teaching the user a lesson about overindulgence.
The cup works via the principle of the siphon, a channel that allows fluid to be transferred from a higher elevation to a lower one while passing through an even higher point. While siphons have been used for thousands of years, the physics of their operation are more complex and mysterious than they might appear, and have been the subject of much experimentation and scientific debate - even up to the present day.
SOURCES:
ncbi.nlm.nih.gov/pmc/articles/PMC3994459
web.archive.org/web/20130729020731/http://www.mindspring.com/~rwramette/nokes.pdf
https://www.phys.uhh.hawaii.edu/documents/TPT-final.pdf
http://hawaii.edu/news/article.php?aId=4128
commons.wikimedia.org/w/index.php?title=File%3AWould_a_siphon_flow_in_a_vacuum_experimental_answers.pdf&page=1
ncbi.nlm.nih.gov/pmc/articles/PMC4667279
sifouniospottery.com/pythagorean-cups
ancient-origins.net/news-history-archaeology/practical-joke-or-practicing-restraint-drinking-vessel-turned-greedy-guests-021789
https://davidson.weizmann.ac.il/en/online/scienceathome/amazing-self-emptying-cup-pythagoras-cup
romanaqueducts.info/siphons/siphons.htm
https://eprints.qut.edu.au/41923/1/The_secret_siphon_eprints.pdf
iopscience.iop.org/article/10.1088/0031-9120/6/5/005/pdf
